The disease Acquired Immunodeficiency Syndrome (AIDS) is the end result of infection by the distinct retroviruses, human immunodeficiency virus type-1 (HIV-1) or type-2 (HIV-2). Several critical points in the virus life cycle have been identified as possible targets for therapeutic intervention. Inhibition of one of these, the transcription of viral RNA to viral DNA (controlled by reverse transcriptase, RT), has provided a number of the current therapies used in treating AIDS. Inhibition of reverse transcriptase provided the first form of treatment for HIV infection with 3xe2x80x2-azido-3xe2x80x2-deoxythymidine (AZT). Since then several inhibitors have been launched, broadly forming two classes: nucleoside analogues and non-nucleosides. As an example of the latter it has been found that certain benzoxazinones, e.g. efavirenz, are useful in the inhibition of HIV RT. However, development of strains of the virus resistant to current RT inhibitors is a constant problem. Therefore, development of compounds effective against resistant strains is an important goal.
Pyrazole derivatives have been described in the literature with different uses (e.g. agrochemistry or treatment of stress-relating illness).
EP 0 627 423 describes pyrazole derivatives and their use as agrohorticultural bactericides.
U.S. Pat. No. 6,005,109 describes pyrazole derivatives and their use in the treatment of stress-relating illness.
U.S. Pat. No. 5,786,302 describes pyrazole derivatives and their use as herbicides.
The present invention provides pyrazole compounds of the general formula 
which are potent inhibitors of the human immunodeficiency virus reverse transcriptase enzyme (HIV RT) which is involved in viral replication. Consequently the compounds of this invention can be advantageously used as therapeutic agents for the treatment of diseases mediated by the human immunodeficiency virus (HIV).
This object can be achieved with compounds of formula I 
wherein
R1 is alkyl or substituted alkyl;
R2 is aryl or substituted aryl;
R3 is hydroxy, amino, azido, hydroxy-C1-4-alkyl, C1-4-alkyl-sulfonyl-amino or a group of the formula xe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Z,
wherein X represents NRxe2x80x3xe2x80x3, O or a single bond; wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl, and
wherein Z is C1-4-alkyl, C1-4-alkoxy or NRxe2x80x3, Rxe2x80x2xe2x80x3; wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl;
A signifies alkyl, substituted alkyl, aryl-methyl, substituted aryl-methyl, aryl-methoxy-methyl, substituted aryl-methoxy-methyl, heterocyclyl-methyl, substituted heterocyclyl-methyl, heterocyclyl-methoxy-methyl or substituted heterocyclyl-methoxy-methyl;
with ethers of compounds of formula I as well as with pharmaceutically acceptable salts of the foregoing.
The term xe2x80x9calkylxe2x80x9d as used herein, and if not specified by the number of carbon atoms, denotes an optionally substituted straight or branched chain hydrocarbon residue containing 1 to 12 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert.-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl including their different isomers. The term xe2x80x9cC1-12-alkylxe2x80x9d denotes a straight or branched chain hydrocarbon residue containing 1 to 12 carbon atoms as defined above. The term xe2x80x9cC1-7-alkylxe2x80x9d denotes a straight or branched chain hydrocarbon residue containing 1 to 7 carbon atoms. The term xe2x80x9cC1-4-alkylxe2x80x9d denotes a straight or branched chain hydrocarbon residue containing 1 to 4 carbon atoms. Suitable substituents for the alkyl group are 1-6 fluorine substituents or 1-3 hydroxy substituents, preferably 1-3 fluorine substituents or 1-2 hydroxy substituents and most preferably 3 fluorine substituents or 1 hydroxy substituent. In case more than one substituent is attached to the alkyl group, these substituents can be identical or different from each other. Alkyl in R1 is preferably a straight or branched chain hydrocarbon residue containing 1 to 12 carbon atoms as defined above. More preferably the alkyl group in R1 is a straight or branched chain hydrocarbon residue containing 1 to 7 carbon atoms. In another preferred embodiment alkyl in R1 is methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert.-butyl. Most preferred alkyl in R1 is isopropyl.
Substituted alkyl for R1 is preferably a straight or branched chain hydrocarbon residue containing 1 to 12 carbon atoms as defined above substituted with 1-6 fluorine substituents, most preferably the trifluoromethyl group.
Alkyl for the substituent A is preferably a straight or branched chain hydrocarbon residue containing 1 to 12 carbon atoms as defined above. More preferred alkyl groups in R1 are straight or branched chain hydrocarbon residues containing 1 to 7 carbon atoms. Most preferred alkyl in R1 is methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl or tert.-butyl.
Substituted alkyl for the substituent A is preferably a straight or branched chain hydrocarbon residue containing 1 to 12 carbon atoms as defined above substituted with 1-3 hydroxy groups, most preferably the hydroxy-methyl group.
The term xe2x80x9chydroxy-C1-4-alkylxe2x80x9d as used herein denotes a C1-4-alkyl, preferably a C1-2-alkyl as defined above which is substituted with a hydroxy group. Examples are hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl, 1-hydroxypropyl, 2-hydroxypropyl, 3-hydroxypropyl, 1-hydroxybutyl, 2-hydroxybutyl, 3-hydroxybutyl, 4-hydroxybutyl.
The term xe2x80x9cC1-4-alkyl-sulfonyl-aminoxe2x80x9d as used herein for the substituent R3 denotes for example a methanesulfonamide, ethanesulfonamide, propanesulfonamide or butanesulfonamide. The NH-function of C1-4-alkyl-sulfonyl-amino can as well be alkylated with C1-4-alkyl as defined above, preferably methyl or ethyl.
The term xe2x80x9calkoxyxe2x80x9d as used herein, denotes a straight or branched chain alkyl-oxy group wherein the xe2x80x9calkylxe2x80x9d portion is as defined above such as methoxy, ethoxy, n-propyloxy, isopropyloxy, n-butyloxy, isobutyloxy, tert.-butyloxy. More preferred alkoxy groups within the invention are methoxy or ethoxy.
Formula xe2x80x9cxe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Zxe2x80x9d as used herein denotes a chemical group wherein X represents NRxe2x80x3xe2x80x3, O or a single bond (wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl); and wherein Z is C1-4-alkyl, C1-4-alkoxy or NRxe2x80x3Rxe2x80x2xe2x80x3 (wherein Rxe2x80x2, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl). Preferably, the formula xe2x80x9cxe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Zxe2x80x9d as used herein denotes a chemical group wherein X represents NRxe2x80x3xe2x80x3 or O (wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl); and wherein Z is C1-4-alkyl, C1-4-alkoxy or NRxe2x80x3Rxe2x80x2xe2x80x3 (wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl). More preferred, the formula xe2x80x9cxe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Zxe2x80x9d as used herein denotes a chemical group wherein X represents NRxe2x80x3xe2x80x3 or O (wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl); and wherein Z is NRxe2x80x3Rxe2x80x2xe2x80x3 (wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl). Most preferred, the formula xe2x80x9cxe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Zxe2x80x9d as used herein denotes a chemical group wherein X represents O (wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl); and wherein Z is NRxe2x80x3Rxe2x80x2xe2x80x3 (wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl). Examples of the chemical group of formula xe2x80x9cxe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Zxe2x80x9d are amino-carbonyl-oxy, methyl-amino-carbonyl-oxy, di-methyl-amino-carbonyl-oxy, amino-carbonyl-amino, methyl-amino-carbonyl-amino, di-methyl-amino-carbonyl-amino, amino-carbonyl-(methyl)-amino, methyl-amino-carbonyl-(methyl)-amino, di-methyl-amino-carbonyl-(methyl)-amino, methoxy-carbonyl-amino, methoxy-carbonyl-(methyl)-amino, ethoxy-carbonyl-amino or ethoxy-carbonyl-(methyl)-amino.
The term xe2x80x9carylxe2x80x9d as used herein denotes an optionally substituted phenyl and naphthyl, both optionally benz-fused to an optionally substituted saturated, partially unsaturated or aromatic monocyclic, bicyclic or tricyclic heterocycle or carbocycle e.g. to cyclohexyl or cyclopentyl. Preferably the term xe2x80x9carylxe2x80x9d as used herein denotes an optionally substituted phenyl group.
Suitable substituents for aryl (preferably phenyl) can be selected from 1-5 substituents selected from C1-4-alkyl, substituted C1-4-alkyl, C1-4-alkoxy, C1-4-alkylthio, fluorine, chlorine, bromine and cyano; wherein substituted C1-4-alkyl means C1-4-alkyl substituted with 1-3 substituents selected from hydroxy, C1-4-alkoxy, CONH2, NRRxe2x80x2 and wherein R and Rxe2x80x2 are independently of each other hydrogen, C1-4-alkyl or xe2x80x94C(xe2x95x90O)CH3.
In case more than one substituent is attached to the aryl group, these substituents can be identical or different from each other.
Aryl in R2 is preferably an unsubstituted or substituted phenyl or naphthyl (preferably phenyl) with suitable substituents selected from 1 to 5 substituents, preferably 1-4 substituents, more preferably 1-3 substituents selected from C1-4-alkyl (preferably C1-2-alkyl), substituted C1-4-alkyl (preferably substituted C1-2-alkyl), C1-4-alkoxy (preferably C1-2-alkoxy), C1-4-alkylthio (preferably C1-2-alkylthio), fluorine, chlorine, bromine and cyano; wherein substituted C1-4-alkyl (preferably substituted C1-2-alkyl) means C1-4-alkyl (preferably C1-2-alkyl) substituted with 1-3 substituents (preferably 1-2 substituents, more preferred 1 substituent) selected from hydroxy, C1-4-alkoxy (preferably C1-2-alkoxy), CONH2 and NRRxe2x80x2; and wherein R and Rxe2x80x2 are independently of each other hydrogen, C1-4-alkyl (preferably C1-2-alkyl) or xe2x80x94C(xe2x95x90O)CH3. In case more than one substituent is attached to the aryl group, these substituents can be identical or different from each other. Preferred substituents for the phenyl group are 1-5 substituents (more preferred 1-3 substituents) selected from C1-4-alkyl, C1-4-alkoxy, C1-4-alkylthio, fluorine, chlorine, bromine and cyano (more preferred fluorine, chlorine, bromine and cyano). Most preferred substituents for the phenyl group are 1-5 substituents (more preferred 1-3 substituents) selected from chlorine and cyano. Examples of substituted aryl groups are 2-methyl-phenyl, 3-methyl-phenyl, 4-methyl-phenyl, 2-ethyl-phenyl, 3-ethyl-phenyl, 4-ethyl-phenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2,5-dimethylphenyl, 2,6-dimethylphenyl, 3,4-dimethylphenyl, 3,5-dimethylphenyl, 3,6-dimethylphenyl, 2,4,6-trimethylphenyl, 3,4,5-trimethylphenyl, 2,3,4-trimethylphenyl, 2,4,5-trimethylphenyl, 2-methoxy-phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 2,6-dimethoxy-phenyl, 3,4-dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2,3-difluorophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 2,6-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl, 3,6-difluorophenyl, 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,3-dichlorophenyl, 2,4-dichlorophenyl, 2,5-dichlorophenyl, 2,6-dichlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 3,6-dichlorophenyl, 2,4,6-trichlorophenyl, 3,4,5-trichlorophenyl, 2,3,4-trichlorophenyl, 2,4,5-trichlorophenyl, 2-bromophenyl, 3-bromophenyl, 4-bromophenyl, 2,3-dibromophenyl, 2,4-dibromophenyl, 2,5-dibromophenyl, 2,6-dibromophenyl, 3,4-dibromophenyl, 3,5-dibromophenyl, 3,6-dibromophenyl, 2-cyano-phenyl, 3-cyano-phenyl, 4-cyano-phenyl, 2,3-di-cyano-phenyl, 2,4-di-cyano-phenyl, 2,5-di-cyano-phenyl, 2,6-di-cyano-phenyl, 3,4-di-cyano-phenyl, 3,5-di-cyano-phenyl, 3,6-di-cyano-phenyl, 2-(hydroxymethyl)phenyl, 3-(hydroxymethyl)phenyl, 4-(hydroxymethyl)phenyl, 2-chloro-4-fluorophenyl, 2-chloro-6-methyl-phenyl, 3-chloro-5-bromo-phenyl, 3-chloro-5-propyl-phenyl, 3-chloro-5-methyl-phenyl, 3-chloro-5-ethyl-phenyl, 3-chloro-5-(hydroxymethyl)-phenyl, 3-chloro-5-cyano-phenyl, 3-chloro-5-(1,2-propanediol)-phenyl or 2-naphthyl. Preferred example for aryl in R2 is 2-chlorophenyl, 3-chlorophenyl, 4-chlorophenyl, 2,3-dichlorophenyl, 2,4-dichlorophenyl, 2,5-dichlorophenyl, 2,6-dichlorophenyl, 3,4-dichlorophenyl, 3,5-dichlorophenyl, 3,6-dichlorophenyl, 2,4,6-trichlorophenyl, 3,4,5-trichlorophenyl, 2,3,4-trichlorophenyl, 2,4,5-trichlorophenyl. More preferred example for aryl in R2 is 3,5-dichlorophenyl.
Aryl in aryl-methyl for the substituent A is as defined above, preferably phenyl.
Substituted aryl in substituted aryl-methyl for the substituent A is as defined above, with suitable substituents selected from 1 to 5 substituents, preferably 1-4 substituents, more preferably 1-3 substituents selected from C1-4-alkoxy (preferably C1-2-alkyl), fluorine, chlorine and bromine. In case more than one substituent is attached to the aryl group, these substituents can be identical or different from each other. Examples for substituted aryl in substituted aryl-methyl are preferably 2-methoxy-phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 2,6-dimethoxy-phenyl, 3,4-dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2,3-difluorophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 2,6-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl or 3,6-difluorophenyl.
Aryl in aryl-methoxy-methyl for the substituent A is as defined above, preferably phenyl.
Substituted aryl in substituted aryl-methoxy-methyl, for the substituent A is as defined above, with suitable substituents selected from 1 to 5 substituents, preferably 1-4 substituents, more preferably 1-3 substituents selected from C1-4-alkyl, C1-4-alkoxy, C1-4-alkylthio, C1-4-alkylamino, hydroxy, cyano, amino, mercapto groups, fluorine, chlorine and bromine. In case more than one substituent is attached to the aryl group, these substituents can be identical or different from each other. Examples for substituted aryl in substituted substituted aryl-methoxy-methyl are 2-methoxy-phenyl, 3-methoxy-phenyl, 4-methoxy-phenyl, 2,3-dimethoxy-phenyl, 2,4-dimethoxy-phenyl, 2,5-dimethoxy-phenyl, 2,6-dimethoxy-phenyl, 3,4-dimethoxy-phenyl, 3,5-dimethoxy-phenyl, 3,6-dimethoxy-phenyl, 2-cyanophenyl, 3-cyanophenyl, 4-cyanophenyl, 2-fluorophenyl, 3-fluorophenyl, 4-fluorophenyl, 2,3-difluorophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 2,6-difluorophenyl, 3,4-difluorophenyl, 3,5-difluorophenyl or 3,6-difluorophenyl.
The term xe2x80x9cheterocyclylxe2x80x9d as used herein denotes an aromatic or non-aromatic monocyclic or bicyclic heterocyclic system which contains 1, 2, 3 or 4 hetero atoms, preferably 1, 2 or 3 hetero atoms, with the hetero atoms being selected from nitrogen, oxygen and sulfur. Examples of heterocyclyl are 2-furyl, 3-furyl, 1-pyrrolyl, 2-pyrrolyl, 2-pyridyl, 3-pyridyl, 4-pyridyl, 1-indolyl, 2-indolyl or 3-indolyl, pyridazin-3-yl, pyridazin-4-yl, 2-thienyl, 3-thienyl, [1,3,4]thiadiazol-2-yl, [1,3,4]thiadiazol-5-yl, tetrahydro-pyran-4-yl, piperidin-2-yl, piperidin-3-yl, piperidin-4-yl, 1H-imidazol-2-yl, 1H-imidazol-4-yl, 1H-imidazol-5-yl, pyrrolidin-1-yl, pyrrolidin-2-yl, pyrrolidin-3-yl, pyrrolidin-4-yl, pyrrolidin-5-yl, pyrimidin-2-yl, pyrimidin-4-yl, pyrimidin-5-yl or pyrimidin-6-yl.
Suitable substituents for heterocyclyl can be selected from 1,2,3 or 4 (where chemically possible), preferably 1 or 2, selected from C1-4-alkyl (preferably C1-2-alkyl), C1-4-alkoxy (preferably C1-2-alkoxy), C1-4-alkylthio (preferably Cl 2-alkylthio), Cl 4-alkylamino (preferably C1-2-alkylamino), hydroxy, cyano, amino, mercapto groups, fluorine, chlorine and bromine.
In case more than one substituent is attached to the aryl group, these substituents can be identical or different from each other.
Heterocyclyl in heterocyclyl-methyl or heterocyclyl-methoxy-methyl for the substituent A is as defined above, preferably 1-furyl, 2-furyl, l-pyrrolyl, 2-pyrrolyl, 1-thiophenyl, 2-thiophenyl, 2-pyridyl, 3-pyridyl or 4-pyridyl, more preferred 2-pyridyl, 3-pyridyl, 4-pyridyl, pyrimidin-2-yl, pyrimidin-4-yl, pyrimidin-5-yl or pyrimidin-6-yl. Preferred heterocyclyl in heterocyclyl-methyl or heterocyclyl-methoxy-methyl is pyridyl, most preferred 4-pyridyl.
Substituted heterocyclyl in substituted heterocyclyl-methyl or substituted heterocyclyl-methoxy-methyl for the substituent A are as defined above. Suitable substituents for heterocyclyl are selected from 1, 2, 3 or 4 substituents, preferably 1, 2 or 3 substituents, more preferably 1 or 2 substituents, and most preferably 1 substituent, wherein these substituents are selected from C1-4-alkyl (preferably C1-2-alkyl), C1-4-alkoxy (preferably C1-2-alkoxy), C1-4-alkylthio (preferably C1-2-alkylthio), C1-4-alkylamino (preferably C1-2-alkylamino), hydroxy, cyano, amino, mercapto groups, fluorine, chlorine and bromine. Preferred substituents for heterocyclyl are selected from 1, 2, 3 or 4 substituents, preferably 1, 2 or 3 substituents, more preferably I or 2 substituents, and most preferably 1 substituent, wherein these substituents are selected from 1-4 substituents selected from C1-4-alkyl, fluorine, chlorine and bromine. More preferred substituents for heterocyclyl are selected from 1, 2, 3 or 4 substituents, preferably 1, 2 or 3 substituents, more preferably 1 or 2 substituents, and most preferably 1 substituent, wherein these substituents are selected from C1-4-alkyl and bromine. Examples for substituted heterocyclyl are 2-methyl-pyridyl, 3-methyl-pyridyl, 4-methyl-pyridyl, 2,3-dimethylpyridyl, 2,4-dimethylpyridyl, 2,5-dimethylpyridyl, 2,6-dimethylpyridyl, 3,4-dimethylpyridyl, 3,5-dimethylpyridyl, 3,6-dimethylpyridyl, 2-methoxy-pyridyl, 3-methoxy-pyridyl, 4-methoxy-pyridyl, 2,3-dimethoxy-pyridyl, 2,4-dimethoxy-pyridyl, 2,5-dimethoxy-pyridyl, 2,6-dimethoxy-pyridyl, 3,4-dimethoxy-pyridyl, 3,5-dimethoxy-pyridyl, 3,6-dimethoxy-pyridyl, 2-fluoro-pyridyl, 3-fluoro-pyridyl, 4-fluoro-pyridyl, 2,3-difluoro-pyridyl, 2,4-difluoro-pyridyl, 2,5-difluoro-pyridyl, 2,6-difluoro-pyridyl, 3,4-difluoro-pyridyl, 3,5-difluoro-pyridyl, 3,6-difluoro-pyridyl, 2-chloro-pyridyl, 3-chloro-pyridyl, 4-chloro-pyridyl, 2,3-dichloro-pyridyl, 2,4-dichloro-pyridyl, 2,5-dichloro-pyridyl, 2,6-dichloro-pyridyl, 3,4-dichloro-pyridyl, 3,5-dichloro-pyridyl, 3,6-dichloro-pyridyl, 2-bromo-pyridyl, 3-bromo-pyridyl, 4-bromo-pyridyl, 2,3-dibromo-pyridyl, 2,4-dibromo-pyridyl, 2,5-dibromo-pyridyl, 2,6-dibromo-pyridyl, 3,4-dibromo-pyridyl, 3,5-dibromo-pyridyl, 3,6-dibromo-pyridyl, 5-bromo-2-methyl-pyrimidin-4-yl, 2-bromo-5-methyl-pyrimidin-4-yl, 5-bromo-6-methyl-pyrimidin-4-yl, 6-bromo-2-methyl-pyrimidin-4-yl, 6-bromo-5-methyl-pyrimidin-4-yl, 5-bromo-pyrimidin-4-yl, 5-methyl-pyrimidin-4-yl, 2-bromo-pyrimidin-4-yl, 2-methyl-pyrimidin-4-yl, 6-bromo-pyrimidin-4-yl or 6-methyl-pyrimidin-4-yl. For all the cited examples for xe2x80x9csubstituted heterocyclylxe2x80x9d these substituents can be at any chemically possible position. For example methylpyridyl means that the methyl substituent may be attached in the 3, 4, 5 or 6 position of a 2-pyridyl or in the 2,4,5 or 6 position of a 3-pyridyl or in the 2, 3, 5 or 6 position of a 4-pyridyl.
Any functional (i.e. reactive) group present in a side-chain may be protected, with the protecting group being a group which is known per se, for example, as described in xe2x80x9cProtective Groups in Organic Synthesisxe2x80x9d, 2nd Ed., T. W. Greene and P. G. M. Wuts, John Wiley and Sons, New York, N.Y., 1991. For example, an amino group can be protected by tert.-butoxycarbonyl (BOC) or benzyloxycarbonyl (Z).
Compounds of formula I which are acidic can form pharmaceutically acceptable salts with bases such as alkali metal hydroxides, e.g. sodium hydroxide and potassium hydroxide; alkaline earth metal hydroxides, e.g. calcium hydroxide, barium hydroxide and magnesium hydroxide, and the like; with organic bases e.g. N-ethyl piperidine, dibenzylamine, and the like. Those compounds of formula (I) which are basic can form pharmaceutically acceptable salts with inorganic acids, e.g. with hydrohalic acids such as hydrochloric acid and hydrobromic acid, sulphuric acid, nitric acid and phosphoric acid, and the like, and with organic acids, e.g. with acetic acid, tartaric acid, succinic acid, fumaric acid, maleic acid, malic acid, salicylic acid, citric acid, methanesulphonic acid and p-toluene sulphonic acid, and the like. The formation and isolation of such salts can be carried out according to methods known in the art.
Preferred embodiments of the invention are novel compounds of formula I wherein
R1 is C1-12-alkyl or C1-12-alkyl substituted with 1-6 fluorines,
preferably wherein
R1 is C1-12-alkyl,
more preferred wherein
R1 is C1-7-alkyl,
most preferred wherein
R1 is C1-4-alkyl;
R2 is aryl or substituted aryl,
wherein substituted aryl means aryl substituted with 1-5 substituents selected from C1-4-alkyl, substituted C1-4-alkyl, C1-4-alkoxy, C1-4-alkylthio, fluorine, chlorine, bromine and cyano; and wherein substituted C1-4-alkyl means C1-4-alkyl substituted with 1-3 substituents selected from hydroxy, C1-4-alkoxy, CONH2 and NRRxe2x80x2,
wherein R and Rxe2x80x2 are independently of each other hydrogen, C1-4-alkyl or xe2x80x94C(xe2x95x90O)CH3,
preferably wherein
R2 is phenyl or substituted phenyl,
wherein substituted phenyl means phenyl substituted with 1-5 substituents selected from C1-4-alkyl, C1-4-alkoxy, C1-4-alkylthio, fluorine, chlorine, bromine and cyano,
more preferred wherein
R2 is substituted phenyl,
wherein substituted phenyl means phenyl substituted with 1-5 substituents selected from fluorine, chlorine, bromine and cyano,
most preferred wherein
R2 is substituted phenyl,
wherein substituted phenyl means phenyl substituted with 1-3 substituents selected from fluorine, chlorine, bromine and cyano;
R3 is hydroxy, amino, azido, hydroxy-C1-4-alkyl, C1-4-alkyl-sulfonyl-amino or a group of the formula xe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Z,
wherein X represents NRxe2x80x3xe2x80x3, O or a single bond; wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl, and
wherein Z is C1-4-alkyl, C1-4-alkoxy or NRxe2x80x3Rxe2x80x2xe2x80x3; wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl,
preferably wherein
R3 is hydroxy, amino, azido, C1-4-alkyl-sulfonyl-amino or a group of the formula xe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Z,
wherein X represents NRxe2x80x3xe2x80x3 or O; wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl, and
wherein Z is C1-4-alkyl, C1-4-alkoxy or NRxe2x80x3Rxe2x80x2xe2x80x3; wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl,
more preferred wherein
R3 is hydroxy or a group of the formula xe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Z,
wherein X represents NRxe2x80x3xe2x80x3 or O; wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl, and
wherein Z is NRxe2x80x3Rxe2x80x2xe2x80x3; wherein Rxe2x80x3Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl,
most preferred wherein
R3 is a group of the formula xe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Z,
wherein X represents NRxe2x80x3 or O; wherein Rxe2x80x3xe2x80x3 is hydrogen or C1-4-alkyl, and
wherein Z is NRxe2x80x3Rxe2x80x2xe2x80x3; wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl;
A signifies C1-12-alkyl, hydroxy-methyl, aryl-methyl, substituted aryl-methyl, aryl-methoxy-methyl, substituted aryl-methoxy-methyl, heterocyclyl-methyl, substituted heterocyclyl-methyl, heterocyclyl-methoxy-methyl or substituted heterocyclyl-methoxy-methyl,
wherein substituted aryl-methyl means aryl substituted with 1-5 substituents selected from C1-4-alkoxy, fluorine, chlorine and bromine, and
wherein substituted aryl-methoxy-methyl means aryl substituted with 1-5 substituents, substituted heterocyclyl-methyl or substituted heterocyclyl-methoxy-methyl means heterocyclyl substituted with 1-4 substituents, the substituents selected from C1-4-alkyl, C1-4-alkoxy, C1-4-alkylthio, C1-4-alkylamino, hydroxy, cyano, amino, mercapto, fluorine, chlorine and bromine,
preferably wherein
A signifies heterocyclyl-methyl, substituted heterocyclyl-methyl or heterocyclyl-methoxy-methyl,
wherein substituted heterocyclyl-methyl means heterocyclyl substituted with 1-4 substituents selected from C1-4-alkyl, fluorine, chlorine and bromine,
more preferred wherein
A signifies heterocyclyl-methyl, substituted heterocyclyl-methyl or heterocyclyl-methoxy-methyl,
wherein substituted heterocyclyl-methyl means heterocyclyl substituted with 1-2 substituents selected from C1-4-alkyl and bromine,
most preferred wherein
A signifies heterocyclyl-methyl;
with ethers of compounds of formula I as well as with pharmaceutically acceptable salts of the foregoing.
A further preferred embodiment of the invention are novel compounds of formula I
wherein
R1 is iso-propyl;
R2 is substituted phenyl,
wherein substituted phenyl means phenyl substituted with 1-3 substituents selected from chlorine and cyano;
R3 is a group of the formula xe2x80x94Xxe2x80x94C(xe2x95x90O)xe2x80x94Z,
wherein X represents O, and
wherein Z is NRxe2x80x3Rxe2x80x2xe2x80x3; wherein Rxe2x80x3, Rxe2x80x2xe2x80x3 are independently of each other hydrogen or C1-4-alkyl;
A signifies pyridyl-methyl;
with ethers of compounds of formula I as well as with pharmaceutically acceptable salts of the foregoing.
Specific embodiments of the present invention are compounds of formula I listed in table 1, as well as their ethers and pharmaceutically acceptable salts thereof:
The useful activity of the compounds of formula I for the treatment of diseases mediated by the human immunodeficiency virus (HIV) can be demonstrated with the following assay methods.
HIV-1 Reverse Transcriptase Assay: Inhibitor IC50 Determination
HIV-1 RT assay was carried out in 96-well Millipore filtermat NOB50 plates using purified recombinant enzyme and a poly(rA)/oligo(dT)16 template-primer in a total volume of 50 xcexcL. The assay constituents were 50 mM Tris/HCl, 50 mM NaCl, 1 mM EDTA, 6 mM MgC2, 5 xcexcM dTTP, 0.1 xcexcCi [3H] dTTP, 5 xcexcg/ml poly (rA) pre annealed to 2.5 xcexcg/ml oligo (dT)16 and a range of inhibitor concentrations in a final concentration of 10% DMSO. Reactions were initiated by adding 5 nM HIV-1 RT and after incubation at 37xc2x0 C. for 30 min, they were stopped by the addition of 50 xcexcl ice cold 20% TCA and allowed to precipitate at 4xc2x0 C. for 30 min. The precipitates were collected by applying vacuum to the plate and sequentially washing with 2xc3x97200 xcexcl of 10% TCA and 2xc3x97200 xcexcl 70% ethanol. Finally the plates were dried and radioactivity counted in a Wallac Microbeta 1450 after the addition of 15 VI scintillation fluid per well. IC50""s were calculated by plotting % inhibition versus log10 inhibitor concentrations.
Antiviral Assay Method
Anti-HIV antiviral activity was assessed using an adaptation of the method of Pauwels et al. {Pauwels et al., 1988, J Virol Methods 20:309-321}. The method is based on the ability of compounds to protect HIV-infected T lymphoblastoid cells (MT4 cells) from cell-death mediated by the infection. The endpoint of the assay was calculated as the concentration of compound at which the cell viability of the culture was preserved by 50% (xe2x80x9850% inhibitory concentrationxe2x80x99, IC50). The cell viability of a culture was determined by the uptake of soluble, yellow 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) and its reduction to a purple insoluble formazan salt. After solubilization, spectrophotometric methods were employed to measure the amount of formazan product.
MT4 cells were prepared to be in logarithmic-phase growth and a total of 2xc3x97106 cells infected with the HXB2-strain of HIV at a multiplicity of 0.0001 infectious units of virus per cell in a total volume of between 200-500 microliters. The cells were incubated with virus for one h at 37xc2x0 C. before removal of virus. The cells are then washed in 0.01 M phosphate buffered saline, pH 7.2 before being resuspensed in culture medium for incubation in culture with serial dilutions of test compound. The culture medium used was RPMI 1640 without phenol red, supplemented with penicillin, streptomycin, L-glutamine and 10% fetal calf serum (GM10).
Test compounds were prepared as 2 mM solutions in dimethyl sulphoxide (DMSO). Four replicate, serial 2-fold dilutions in GM10 were then prepared and 50 microliters amounts placed in 96-well plates over a final nanomolar concentration range of 625-1.22. Fifty microliters GM10 and 3.5xc3x97104 infected cells were then added to each well. Control cultures containing no cells (blank), uninfected cells (100% viability; 4 replicates) and infected cells without compound (total virus-mediated cell death; 4 replicates) were also prepared. The cultures were then incubated at 37xc2x0 C. in a humidified atmosphere of 5% CO2 in air for 5 d.
A fresh solution of 5 mg/mL MTT was prepared in 0.01 M phosphate buffered saline, pH 7.2 and 20 microliters added to each culture. The cultures were further incubated as before for 2 h. They were then mixed by pipetting up and down and 170 microliters of Triton X-100 in acidified isopropanol (10% v/v Triton X-100 in 1:250 mixture of concentrated HCl in isopropanol). When the formazan deposit was fully solubilized by further mixing, the absorbance (OD) of the cultures was measured at 540 nm and 690 nm wavelength (690 nm readings were used as blanks for artefacts between wells). The percent protection for each treated culture can be calculated from the equation:       %    ⁢          xe2x80x83        ⁢    Protection    =                              (OD drug-treated cultures)                -                  (OD untreated virus control cultures)                                      (OD uninfected cultures)                -                  (OD untreated virus control cultures)                      xc3x97    100    ⁢    %  
In the assay, compounds of the formula I range in IC50 activity from about 0.5 to about 5000 nM, with preferred compounds having a range of about 0.5 to about 750 nM, more preferably about 0.5 to 300 nM, and most preferably about 0.5 to 50 nM.
The processes for the preparation of compounds of formula I, their ethers and pharmaceutically acceptable salts as well as their compounds, whenever prepared by these processes are also an object of the present invention.
The compounds of the present invention can be prepared in accordance with known methods, e.g. as shown in the following schemes: 
wherein R1 and R2 are as described in formula I, A signifies a group arylmethyl, substituted aryl-methyl, aryl-methoxy-methyl , substituted aryl-methoxy-methyl, heterocyclyl-methyl or substituted heterocyclyl-methyl as described in formula I, R4 is heterocyclyl or substituted heterocyclyl as defined for compounds of formula I and Hal represents chlorine, bromine or iodine.
In reaction scheme 1, step 1 is carried out in that a hydrazine derivative of formula II is reacted with compound of formula III (commercially available from Aldrich or Fluka) to obtain the pyrazole derivative of formula IV. The reaction is conveniently carried out in the presence of a carboxylic acid, for example acetic acid, in an appropriate solvent such as halogenated hydrocarbons (e.g. dichloromethane or trichloromethane) or hydrocarbons (e.g. cyclohexane, methyl cyclohexane, decaline, benzene, toluene, o-xylene, m-xylene or p-xylene), preferably toluene. Further, the reaction is carried out at a reaction temperature from room temperature to boiling temperature of the reaction mixture, preferably at a reaction temperature between about 50xc2x0 C. and about 150xc2x0 C.
In step 2 of the reaction scheme, the 5-hydroxy position of pyrazole derivative of formula IV is chlorinated and formylated with a suitable agent. A suitable agent is for example (COCl)2, SOCl2 or POCl3 in combination with N,N-dimethylformamide or N-methylformanilide to obtain the 5-chloro-4-formylpyrazole derivative of formula V. The reaction is conveniently carried out under an inert atmosphere such as nitrogen or argon atmosphere at a reaction temperature from room temperature to boiling temperature of the reaction mixture. Preferably, the reaction is carried out in the presence of POCl3 and N,N-dimethylformamide at a reaction temperature between about 50xc2x0 C. and about 120xc2x0 C., more preferred at a reaction temperature between about 90xc2x0 C. and about 110xc2x0 C.
In step 3 of the reaction scheme, compound of formula V is reacted with a thiole derivative of formula VI (agents are commercially available or can be synthesized according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons), to obtain the pyrazole derivative of formula VII. The reaction is carried out in an appropriate solvent in the presence of a base such as n-BuLi, sodium hydride, trialkylamine (e.g. trimethylamine or triethylamine), potassium carbonate, sodium carbonate, magnesium carbonate, calcium carbonate, preferably potassium carbonate. Further, the reaction is conveniently carried out under an inert atmosphere such as nitrogen or argon atmosphere at a reaction temperature from 0xc2x0 C. to boiling temperature of the reaction mixture, preferably at a reaction temperature between about 10xc2x0 C. and about 180xc2x0 C., more preferred at a reaction temperature from 70xc2x0 C. to 130xc2x0 C. of the reaction mixture. Appropriate solvents for the reaction are THF or polar aprotic solvents such as dimethylsulfoxide (DMSO), dimethylacetamide or N,N-dimethylformamide (DMF), preferably DMF.
The thiole derivative of formula VI can as well be derivatised for example in the following way: Commercially available bromo-substituted thiole derivative of formula VI is converted to the corresponding cyano-substituted thiole derivative according to methods known in the art for example textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
In step 4 of the reaction scheme the pyrazole of formula VII is derivatised with a Grignard reagent R4MgHal of formula VIII, wherein R4 is heterocyclyl or substituted heterocyclyl as defined for compounds of formula I and Hal represents chlorine, bromine or iodine, preferably chlorine (commercially available or synthesised according to textbooks on organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms and Structurexe2x80x9d, 4th ed. John Wiley and Sons) to obtain the corresponding substituted hydroxy-methyl-pyrazole derivative of formula IX. The derivatisation reaction is conveniently carried out in an inert solvent for example ethers such as tetrahydrofuran, diethyl ether, dibutyl ether, dioxane, diglyme or a mixture of the mentioned solvents, preferably tetrahydrofuran at a reaction temperature between about xe2x88x9210xc2x0 C. and about 60xc2x0 C., preferably at a reaction temperature between about 0xc2x0 C. and about 40xc2x0 C., more preferred at room temperature. In general, the derivatisation reaction can also be carried out as described in textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons.
In step 5 of the reaction scheme, the substituted hydroxy-methyl group of compound of formula IX is reduced to the corresponding methylene group, to obtain the compound of formula X. The reaction is conveniently carried out in the presence of trialkylsilane such as trimethylsilane, triethylsilane or tripropylsilane, preferably triethylsilane, dissolved in mineral acids such as trifluoroacetic acid (TFA) or in Lewis acids such as SnCl4 (described in D. L. Comins et al., Tet. Lett., 1986, 27, 1869). Further, the reaction is carried out at a reaction temperature from 0xc2x0 C. to 80xc2x0 C., preferably at a reaction temperature between about 5xc2x0 C. and about 50xc2x0 C.
The reduction reaction can also be carried in the presence P2I4 as described in EP 0627423.
The reduction reaction of the substituted hydroxy methyl group of compound of formula IX can also be carried in the presence of NaI, (CH3)3SiCl and HBr or as described in textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). When the hydroxy group is converted to a leaving group such as a mesylate or sulphonate, preferably a mesylate, the reaction can then be carried out in the presence of Zn and acetic acid (described in J. E. Lynch et al., J. Org. Chem., 1997, 62, 9223-9228).
In step 6 of the reaction scheme, the carboxylic ester group of compound of formula X is reduced to a hydroxy-methyl group, to obtain the corresponding compound of formula Ia. The reaction is carried out in the presence of a reducing agent such as lithium aluminium hydride. Preferably, the reaction is carried out by treating the compound of formula X under nitrogen atmosphere with a reducing agent for example LiAlH4, LiBH4, BH3*S(CH3)2, iso-Bu2AlH or Vitride(copyright), in an inert solvent such as ethers for example anhydrous diethyl ether, THF of dioxane at a reaction temperature from 0xc2x0 C. to room temperature. More preferred, the reaction is carried out with LiAlH4 and ethers.
In step 7 of the reaction scheme, the hydroxy-methyl function of the pyrazole derivative of formula Ia is derivatised to the primary carbamate of formula Ib, e.g. using trichloroacetyl isocyanate of formula XI. The pyrazole derivative of formula Ia is conveniently dissolved in a suitable organic solvent such as dichloromethane or chloroform and the reagent trichloroacetyl isocyanate of formula XI is added at a reaction temperature from xe2x88x9210xc2x0 C. to 5xc2x0 C. The work up involves use of bases such as sodium or potassium carbonate followed by purification using standard procedures. Other methods known in the art can effect this transformation, such as chlorosulfonyl isocyanate or trimethylsilyl isocyanate.
The amino-function of compound of formula Ib can also be mono or dialkylated to obtain the corresponding C1-4-alkyl substituted amino function. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
In step 8 of the reaction scheme, the hydroxy-methyl function of the pyrazole derivative of formula Ia is derivatised to the corresponding azido of formula Ic, e.g. using sodium azide or diphenylphosphoryl azide in standard procedures according to methods known from textbooks on organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons.
In step 9 of the reaction scheme, compound Ic is reduced to a corresponding primary amine of formula Id. The reduction reaction to the primary amine of formula Id is carried out by hydrogenation with standard catalysts such as 10% palladium on carbon in suitable solvents, such as ethyl acetate, methanol or ethanol, or with a trialkyl or aryl phosphine (e.g. trimethylphosphine, triethylphosphine or triphenylphosphine).
In step 10, 11 and 12 of the reaction scheme, the primary amine function of compound of formula Id is acylated, sulfonylated or reacted with isocyanates, to obtain the corresponding compounds of formula Ie, If and Ig according to methods known from textbooks on organic chemistry e.g. from J; March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons. These are standard reactions of which there are many combinations of reagents. Acylation (step 10) may be achieved via acid chlorides or other activated carbonyl compounds such as activated carboxylic acids, for example with C1-4-alkyl chloroformate (e.g. methyl chloroformate) in the presence of an amine (e.g. trimethylamine or triethylamine, preferably triethylamine) and dichloromethane as solvent at room temperature. The sulfonylation reaction (step 11) is carried out via sulfonyl chlorides (e.g. C1-4-alkyl sulfonyl chlorides such as methyl sulfonyl chloride) using a base such as triethylamine, N-methyl morpholine or N-ethyl morpholine, and dichloromethane as solvent at room temperature. The reaction with isocyanates (step 12) is carried out in that compound of formula Id is reacted with trichloroacetyl isocyanate of formula XI as described for step 7, to obtain a compound of formula Ig. The amino-function of compound of formula Ig can also be mono or dialkylated to obtain the corresponding C1-4-alkyl substituted amino function. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
The reactions according to steps 10, 11 and 12 may be conducted in suitable solvents known to those skilled in the art, for example, dichloromethane, chloroform, dioxane, dimethyformamide or tetrahydrofuran.
The NH-function of compounds of formula Ie, If or Ig can be alkylated with C1-4-alkyl, preferably methyl or ethyl. The alkylation reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). 
wherein R1 and R2 are as described in formula I and wherein A signifies a group A signifies a group aryl-methyl, substituted aryl-methyl, aryl-methoxy-methyl, substituted aryl-methoxy-methyl, heterocyclyl-methoxy-methyl or substituted heterocyclyl-methoxy-methyl as described in formula I.
In reaction scheme 2, step 1 is carried out in that the aldehyde of formula VII is reduced in the presence of a reducing agent to obtain the corresponding hydroxy-methyl derivative of formula XII. Reducing agents conveniently used for the reaction are preferably sodium borohydride or other reducing agents such as lithium borohydride, sodium triacetoxyborohydride, hydrogen over a catalyst or reducing agents known in the art applied according to known methods described in textbooks on organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms and Structurexe2x80x9d, 4th ed. John Wiley and Sons. The reduction reaction is conveniently carried out in an organic solvent for example alcoholic solvents such as methanol, ethanol, propanol, butanol, octanol or cyclohexanol, preferably methanol or ethanol or ethers such as tetrahydrofuran, diethyl ether, dibutyl ether, dioxane or diglyme, preferably tetrahydrofuran or a mixture of the mentioned solvents such as methanol and tetrahydrofuran or ethanol and tetrahydrofuran. The reaction is carried out at a reaction temperature between about xe2x88x9210xc2x0 C. and about 60xc2x0 C., preferably at room temperature. The reduction reaction can also be carried out as described in textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons.
In step 2 of the reaction scheme, the hydroxy-methyl function of compound of formula XII is converted to the corresponding bromo-methyl derivative of formula XIII according to standard procedures according to methods known from textbooks on organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons. A possible method for the preparation of a bromide derivative of formula XIII is by using tetrabromomethane in the presence of triphenylphosphine in dichloromethane, at room temperature.
In step 3 of the reaction scheme, the bromide of formula XIII is reacted with a heterocyclyl-methanol compound of formula XIV to obtain the corresponding pyrazole derivative of formula XV. The reaction is conveniently carried out according to methods known from textbooks on organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms and Structurexe2x80x9d, 4th ed. John Wiley and Sons). The reaction is for example carried out in the presence of a base such as sodium hydride, lithium hydride, potassium carbonate or triethylamine in an appropriate organic solvent such as tetrahydrofuran (THF) or polar aprotic solvents like dimethylsulfoxide (DMSO), N,N-dimethylacetamide or N,N-dimethylformamide (DMF), preferably DMF or THF, at a reaction temperature between about xe2x88x9210xc2x0 C. and about 60xc2x0 C., preferably at room temperature.
In step 4 of the reaction scheme, the carboxylic ethyl function of compound of formula XV is reduced with an appropriate reducing agent to obtain the corresponding hydroxy-methyl derivative of formula Ih. The reaction is conveniently carried under nitrogen atmosphere with a reducing agent for example LiAlH4, LiBH4, BH3*S(CH3)2, iso-Bu2AlH or Vitride(copyright), in an inert solvent such as ethers for example anhydrous diethyl ether, THF of dioxane at a reaction temperature from 0xc2x0 C. to room temperature. Preferably, the reaction is carried out with LiAlH4 in an ether such as THF. Subsequently a solution of ammonium chloride is added to yield to a compound of the formula Ih. After the reaction, the product is worked up in a manner known in the art for example extracted with ethyl acetate, dried over anhydrous magnesium sulphate and finally the organic solvent is evaporated.
In step 5 of the reaction scheme, the hydroxy-methyl derivative of formula Ih is derivatised to the primary carbamate of formula Ii. The reaction is carried out with trichloroacetyl isocyanate of formula XI as described for reaction scheme 1 (step 7).
The hydroxy function of compound of formula Ih can also be acylated to obtain the corresponding compound of formula I wherein m=0, X=O and Z=C1-4-alkyl. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
The hydroxy function of compound of formula Ih can also be transformed to obtain the corresponding compound of formula I wherein m=0, X=O and Z=C1-4-alkoxy. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). The amino-function of compound of formula Ii can also be mono or dialkylated to obtain the corresponding C1-4-alkyl substituted amino function. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
Compound of formula Ih is reacted according the methods described in reaction scheme 1 (step 8-12) and thereby the corresponding pyrazole derivatives are obtained, wherein A signifies heterocyclyl-methoxy-methyl or substituted heterocyclyl-methoxy-methyl as described in formula I. 
wherein R1, R2 and A are as described in formula I.
In reaction scheme 3, step 1 is carried out in that the hydroxymethyl derivative of formula Ia is chlorinated to give the corresponding chloromethyl derivative of formula XVI according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). The reaction can for example be carried out in the presence of SOCl2 as chlorinating agent. The hydroxymethyl derivative of formula Ia can also be converted to the corresponding iodide, bromide, mesylate or tosylate according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
In step 2 of the reaction scheme, the chloromethyl derivative of formula XVI is reacted with potassium cyanide in the presence of potassium iodide and DMF, to give the corresponding cyanomethyl derivative of formula Ij, according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). The reaction can as well be carried out with alternative solvents such as DMSO, acetone, acetonitrile, ethanol (and other alcohols)/water mixtures. An optional additive is 18-crown-6.
In step 3 of the reaction scheme, the cyano group of compound of formula Ij is hydrolysed to obtain the corresponding carboxylic acid of formula Ik according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). The reaction is for example carried out in the presence of potassium hydroxide and 1-methoxy-2-hydroxy-ethane. The reaction can as well be carried out in sodium hydroxide or mineral acids, and alternative solvents are methanol, ethanol, water or mixtures thereof.
In step 4 of the reaction scheme, the carboxylic acid group of formula Ik is reduced to obtain the corresponding alcohol of formula II. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons), for example in the presence of a reducing agent such as BH3, BH3*S(CH3)2 or LiAlH4 (all commercially available) in an inert solvent such as ethers for example anhydrous diethyl ether, THF of dioxane at a reaction temperature from 0xc2x0 C. to room temperature. More preferred, the reaction is carried out with BH3 in the presence of ethers.
In step 5 of the reaction scheme, the carboxylic acid of formula Ik is derivatised with an amine of formula XVII to obtain the corresponding amide of formula Im according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
The amino-function of compound of formula Im can also be alkylated to obtain the corresponding C1-4-alkyl substituted amino function. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). 
wherein R1, R2 and A are as described in formula I and Y signifies a leaving group.
In reaction scheme 4, step 1 is carried out in that the hydroxymethyl derivative of formula Ia is alkylated with a compound of formula XVIII, wherein Y signifies a leaving group, to obtain the corresponding ether of formula In according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). A leaving group is for example chlorine, bromine, iodine or mesylate (bromine is preferred). The reaction is for example carried out with a compound of formula XVIII in the presence of a base such as sodium hydride or potassium carbonate.
In step 2 of the reaction scheme, the ester of formula In is hydrolysed to obtain the corresponding carboxylic acid and subsequently derivatised, to obtain the corresponding amide of formula lo according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). The derivatisation reaction can be carried out for example with an amine of formula XVII or with ammonia. The amino-function of compound of formula Io can also be alkylated to obtain the corresponding C1-4-alkyl substituted amino function. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). 
wherein R1, R2 and A are as described in formula I.
In reaction scheme 5, the reaction is carried out in that the primary amine of formula Id is derivatised with caboxylic acid of formula XIX (commercially available or prepared according to methods known in the art), to obtain the corresponding amide of formula Ip. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons).
The NH-function of compounds of formula Ip can be alkylated with C1-4-alkyl, preferably methyl or ethyl. The alkylation reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). 
wherein R1, R2 and A are as described in formula I.
In reaction scheme 6, step 1 is carried out in that the carboxylic acid group of compound of formula Ik is alkylated with C1-4-alkyl, preferably methyl or ethyl, to obtain compound of formula Iq. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). In a more preferred way, the esterification is carried out via an activated acid derivative (e.g. acid chloride) and an alcohol.
In step 2 of the reaction scheme, the the carboxylic acid group of compound of formula Ik is alkylated with C1-4-alkyl, preferably methyl or ethyl, to obtain the corresponding C1-4-alkyl-carbonyl-methyl substituted pyrazole compound of formula Ir. The reaction is carried out according to methods known from textbooks about organic chemistry e.g. from J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). 
wherein R1 and R2 are as described in formula I.
In reaction scheme 7, step 1 is carried out in that the aldehyde function of compound of formula VII is reacted via a Wittig-Horner reaction with dialkyl phosphonate of formula (EtO)2P(xe2x95x90O)(CH3). The reaction is carried out similar the method described in the literature, for example in the presence of a strong base such as n-BuLi or preferably sodium hydride in an organic solvent for example anhydrous ethers such as diethyl ether, dibutyl ether, dioxane, preferably anhydrous tetrahydrofuran under inert atmosphere such as nitrogen or argon atmosphere at a reaction temperature from 0xc2x0 C. to 80xc2x0 C., preferably at a reaction temperature between about 5xc2x0 C. and about 50xc2x0 C. Optionally, olefinic compound of formula Ic can be obtained through other coupling reactions for example the Wittig reaction.
The Wittig-Horner reaction can also be carried out with dialkyl phosphonates of formula (EtO)2P(xe2x95x90O)xe2x80x94(C1-11alkyl) (commercially available or synthesized according to known methods in the art) to a corresponding olefinic compound of formula XX.
In the second step of the reaction, the olefinic group of compound of formula XX is hydrogenated to the corresponding compound of formula XXI. The reaction is carried out similar to methods described in the literature, for example under hydrogen in the presence of a hydrogenation catalyst in an appropriate solvent at a reaction temperature from 0xc2x0 C. to 80xc2x0 C., preferably at a reaction temperature between about 5xc2x0 C. and about 50xc2x0 C. The hydrogen pressure can be between about 0 atm and about 100 atm, preferably between about 0 atm and about 50 atm and most preferred between about 0 atm and about 20 atm. The hydrogenation catalyst used for this reaction can be one of the commonly known catalysts such as noble metals (e.g. Pt, Pd or Rh) on supporting materials such as activated carbon or Al2O3, or generally as described in textbooks about organic chemistry e.g. J. March (1992), xe2x80x9cAdvanced Organic Chemistry: Reactions, Mechanisms, and Structurexe2x80x9d, 4th ed. John Wiley and Sons). Preferred hydrogenation catalysts are Pd on activated carbon or Raney-Nickel. Appropriate solvents for the hydrogenation reaction are organic solvent such as alcohols (e.g. methanol, ethanol, propanol, butanol, octanol or cyclohexanol), ethers (e.g. tetrahydrofuran, diethyl ether, dibutyl ether or dioxane), ketones (e.g. acetone, butanone or cyclohexanone), polar aprotic solvents such as dimethylsulfoxide (DMSO) or dimethylacetamide N, esters (e.g. ethyl acetate), halogenated hydrocarbons (e.g. dichloromethane or trichloromethane), hydrocarbons (e.g. cyclohexane, methyl cyclohexane, decaline, benzene, toluene, o-xylene, m-xylene or p-xylene) or a mixtures of the mentioned solvents. Preferred solvents are ester, most preferred solvent is ethyl acetate.
In step 3 of the reaction scheme, the carboxylic ester group of compound of formula XXI is reduced to a hydroxy-methyl group, to obtain the corresponding compound of formula Is. The reaction is carried out in the presence of a reducing agent such as lithium aluminium hydride. Preferably, the reaction is carried out by treating the compound of formula XXI under nitrogen atmosphere with a reducing agent for example LiAlH4, LiBH4, BH3*S(CH3)2, iso-Bu2AlH or Vitride(copyright), in an inert solvent such as ethers for example anhydrous diethyl ether, THF of dioxane at a reaction temperature from 0xc2x0 C. to room temperature. More preferred, the reaction is carried out with LiAlH4 and ethers.
In step 4 of the reaction scheme, the hydroxy-methyl function of the pyrazole derivative of formula Is is derivatised to the primary carbamate of formula It, e.g. using trichloroacetyl isocyanate of formula XI. The pyrazole derivative of formula Ia is conveniently dissolved in a suitable organic solvent such as dichloromethane or chloroform and the reagent trichloroacetyl isocyanate of formula XI is added at a reaction temperature from xe2x88x9210xc2x0 C. to 5xc2x0 C. The work up involves use of bases such as sodium or potassium carbonate followed by purification using standard procedures. Other methods known in the art can effect this transformation, such as chlorosulfonyl isocyanate or trimethylsilyl isocyanate.
The compounds of the present invention and pharmaceutical compositions containing the same are useful as chemotherapeutic agents, inhibitors of viral replication and modulators of the immune system, and can be used for the treatment of diseases mediated by the human immunodeficiency virus (HIV) other viral diseases such as retroviral infections (either alone or in combination with other antiviral agents such as interferon or derivatives thereof, such as conjugates with polyethylene glycol).
They can be used alone, or in combination with other therapeutically active agents, for example, an immunosuppressant, a chemotherapeutic agent, an anti-viral agent, an antibiotic, an anti-parasitic agent, an anti-inflammatory agent, an anti-fungal agent and/or an anti-vascular hyperproliferation agent.
It will be understood that references herein to treatment extend to prophylaxis as well as to treatment of existing conditions. Treatment of a disease or condition, as used herein, also includes preventing, inhibiting, regressing, reversing, alleviating or relieving the disease or condition, or the clinical symptoms thereof. The term xe2x80x9csubjectxe2x80x9d as used herein refers to animals, including humans and other mammals.
The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.
The pyrazole derivatives provided by the present invention can be used together with a therapeutically inert carrier as medicaments in the form of pharmaceutical preparations. The pharmaceutical preparations can be administered enterally, such as orally, in the form of tablets, coated tablets, dragees, hard and soft gelatine capsules, solutions, emulsions or suspensions, or nasally, e.g. in the form of nasal sprays. They can also be administered rectally, e.g. in the form of suppositories, or parenterally, (e.g. intramuscularly, intravenously, or subcutaneously), for example, in the form of injection solutions.
For the manufacture of pharmaceutical preparations the pyrazole derivatives can be formulated with therapeutically inert, inorganic or organic carriers.
Lactose, corn starch or derivatives thereof, talc, stearic acid or its salts can be used, for example, as such carriers for tablets, coated tablets, dragees and hard gelatine capsules.
Suitable carriers for soft gelatine capsules are, for example, vegetable oils, waxes, fats, semi-solid and liquid polyols and the like.
Suitable carriers for the manufacture of injection solutions are, for example, water, saline, alcohols, polyols, glycerine, vegetable oils and the like. Natural or hardened oils, waxes, fats, semi-liquid or liquid polyols and the like are suitable carriers for the manufacture of suppositories. The pharmaceutical preparations of the present invention may also be provided as sustained release formulations or other appropriate formulations.
The pharmaceutical preparations can also contain preservatives, solubilizers, stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavourants, salts for adjustment of the osmotic pressure, buffers, masking agents or antioxidants.
The pharmaceutical preparations may also contain other therapeutically active agents such as those mentioned above.
The pyrazole derivatives provided by the invention in the treatment of an immune mediated condition or disease, a viral disease, a bacterial disease, a parasitic disease, an inflammatory disease, a hyperproliferative vascular disease, a tumor, or cancer.
The dosage can vary within wide limits and will, of course, be adjusted to the individual requirements in each particular case.
Dosage levels of between about 0.01 and about 100 mg/kg body weight per day in monotherapy and/or in combination therapy are commonly administered from about 1 to 5 times per day. A typical preparation will contain from about 5% to 95% active compound (w/w). The daily dosage can be administered as a single dosage or in divided dosages.
The pyrazole derivatives provided by the present invention or the medicaments thereof may be for use in monotherapy and/or combination therapy, i.e. the treatment may be in conjunction with the administration of one or more additional therapeutically active substance(s). When the treatment is combination therapy, such administration may be concurrent or sequential with respect to that of the pyrazole derivatives of the present invention. Thus, concurrent administration, as used herein, includes administration of the agents in conjunction or combination, together, or before or after each other.
With regard to the starting materials that are known compounds some of these may be purchased from commercial suppliers. Other starting materials that are known and their analogues can be prepared by methods well known in the art. Examples of compounds available from commercial suppliers, and citations to the synthesis of other compounds and their analogues are provided in the following:
The described NMR spectra were recorded on a Bruker DRX 400 MHz spectrometer with the probe temperature set at 300 K.
The mass spectra indicated by xe2x80x9c(M+; EI)xe2x80x9d, were recorded under electron impact conditions (EI), on a THERMOQUEST MAT95 S with a source temperature of 200xc2x0 C. Other mass spectra were recorded under electrospray ionization spectra (ESI) conditions, on one of the following machines:
THERMOQUEST SSQ 7000 [Solvent 0.085% TFA in 90% Acetonitrile/water; flow rate 100 microliters/minute; capillary 250xc2x0 C.; spray voltage 5 KV; sheath gas 80 psi], or
LC-MS system (liquid chromatograph coupled to mass spectrum) THERMOQUEST TSQ 7000 ELECTROSPRAY or MICROMASS PLATFORM ELECTROSPRAY [Solvent 0.1% TFA in water or 0.085% TFA in 90% acetonitrile/water or 0.085% TFA in acetonitrile].
In the following examples the abbreviations used have the following significations:
min minute(s)
h hour(s)
d day(s)
Vitride(copyright) sodium bis(2-methoxyethoxy)aluminum hydride (Fluka)
The following examples illustrate the present invention: